So much of this story is ugly and twisted that it's best to begin with something beautiful and good.

Christina Green is walking eagerly through a sun-splashed Arizona Saturday morning, a busy girl on her way to the next adventure. She is 9 going on 29, with mahogany bangs and one of those great third-grader smiles, with the grownup choppers looming in front and the baby teeth so teensy by comparison. She wants to be an adult "so bad," her babysitter has observed  but for now she's a just about perfect kid. She loves baseball and Beyoncé Knowles, and her daddy calls her Princess. For Christmas, she asked to volunteer at a soup kitchen.
(See TIME's photo-essay "Mourning the Victims of the Arizona Shooting.")

To date, Christina has planned to make her living as a major league ballplayer, and you shouldn't count her out. She has the bloodlines: her grandfather, Dallas Green, managed the Phillies to a World Series title, and her father John is a scout for the Dodgers. And she has the grit. But recently her classmates at Mesa Verde Elementary elected her to the student council, which has inspired a family friend to introduce Christina to another possible career. That's why she's here, in the parking lot of La Toscana Village, a strip shopping center in Tucson's northern hills, where Representative Gabrielle Giffords is hosting a meet-and-greet with her constituents.

"My 1st Congress on Your Corner starts now," Giffords tweeted from her iPad two minutes before 10 a.m. "Please stop by to let me know what is on your mind." Two days earlier, when members of Congress took turns reading the Constitution on the floor of the House of Representatives, Giffords was called on to recite the First Amendment, the one guaranteeing the right of Americans to peaceably assemble and petition their government. Now she is honoring those words.

Christina Green's big, chocolaty eyes take in this scene of government the way it's supposed to be, as accessible as the nearby Safeway. Giffords is a Democrat in a Republican-leaning district that is struggling with the divisive issues of immigration and border security. So this won't be a lovefest. Some of those peaceably assembling are there to tell Giffords how much they admire her, and some intend to give her a piece of their mind.
(See more about Gabrielle Giffords.)

That's the way it's supposed to be. The way it is, day in and day out, in places all over this country. Rational exchanges among reasonable people with differing views. The scene is so routine, so mundane  the grocery store and the folding chairs and the elected official nodding attentively  that we lose sight of the wonder in it. But this is what normal looks like. Pay attention.

Because a taxicab has pulled into the parking lot, carrying a man who is at war with normal. And what he is about to do will unleash other forces also at war with normal, people who are turning our politics into a freak show for their own cynical or sanctimonious reasons. Jared Loughner, wearing a hoodie and sunglasses and having got change from a Safeway cashier to pay the cabdriver, is now walking up to Representative Giffords and leveling a Glock 19 pistol at her head. The ugly and twisted part comes next.